Oh, back to your first post, in my experience, you can increase the current Silverlight 3 viewer's performance quite a bit by simply making your window smaller.
As to Photos+Points mode, it's still available in Silverlight (just press the [P] key, after clicking the viewer), but you're right - the only way to have all the points on all the time is to use the D3D viewer.
I am curious about your second post where you say, "...Once the point cloud has loaded, the picture / cloud view along with the frame rate and cool transitions just make the more compelling.". I understand what you're talking about as far as all points always displaying and the frame rate, but which transitions are missing from the Silverlight viewer? The only one that comes to my mind is the transition from 3D to 2D view in D3D.